Late last night, word began circulating that entrepreneur Dennis Tito — who, in 2001, became the world's first space tourist — intends to launch a privately backed mission to Mars in 2018. Details will be announced next week, but initial reports indicate that the expedition will be round-trip and last 501 days.

Most significantly, it will involve human crew members. Can we really send humans to Mars and back by 2020? We're very skeptical, but it's certainly conceivable. Here's why.

First let's bring you up to speed. Speculation kicked into high gear late last night when news of an historic "Mission for America" — to be announced at a press conference next week — arrived in the form of a media advisory. Titled "The Planets Are Aligning for a Once-in-a-Generation Space Journey," the press release was issued by aerospace marketing firm Griffin Communications Group on behalf of the Inspiration Mars Foundation, a mysterious entity billed as a "newly founded nonprofit organization led by American Space traveler and entrepreneur Dennis Tito." (Pictured below is Tito in 2001 during final preparations for his flight to the ISS.)

Does it mention a 2018 launch date? Yes. Roundtrip journey? Check. 501-day mission? Yep. But a "daring manned voyage" to Mars? A voyage CNET reported 72-year-old Dennis Tito (77 by January, 2018, mind you) intends to carry out himself? No and no. It seemed... unlikely to say the least. Where would so ambitious a project get its funding? Where's the technology?

But now, Jeff Foust of NewSpace Journal, has dug up some information that indicates Tito is, in fact, intending to announce a manned, round-trip mission to Mars.

Doing it with the help of SpaceX

Upon close inspection of the program schedule for next month's IEEE Aerospace Conference in Montana, Foust discovered that Tito is scheduled to host a session on Sunday, March 3 with a rather telling title: "Feasibility Analysis for a Manned Mars Free Return Mission in 2018.″ Listed co-authors include John Carrico, Grant Anderson, Michel Loucks, Taber Mac Callum, Thomas Squire and Jonathan Clark — all of whom will join Tito at next week's Inspiration Mars Foundation press conference.

[NewSpace Journal] obtained a copy of the paper Tito et al. plan to present at the conference, discussing a crewed free-return Mars mission that would fly by Mars, but not go into orbit around the planet or land on it. This 501-day mission would launch in January 2018, using a modified SpaceX Dragon spacecraft launched on a Falcon Heavy rocket. According to the paper, existing environmental control and life support system (ECLSS) technologies would allow such a spacecraft to support two people for the mission, although in Spartan condition. "Crew comfort is limited to survival needs only. For example, sponge baths are acceptable, with no need for showers," the paper states... [adding] that if they miss this favorable 2018 opportunity, the next chance to take advantage of this favorable trajectory would be in 2031.

To recap: this mission will not take humans to the surface of Mars. Nor is it an orbital mission. This is a fly by, aided by a modified SpaceX Dragon capsule (which, last year, became the first commercial spacecraft in history to dock with the International Space Station) and the company's as-yet-untested spaceflight launch system, the Falcon Heavy Rocket, a concept video of which is featured below. Oh — and it's all playing out on a rather cramped schedule.

If Tito can get the funding he needs; if a modified Dragon Capsule can prove itself worthy of human passengers; if the Falcon Heavy can be ready for a January 2018 launch (just a few in a long list of big to very big "ifs") — then Tito's plan is toeing tantalizingly close at the line separating achievable from downright impractical.

Meeting Challenges

Said line is the very definition of fine. A thoroughly vetted and fully functional Falcon Heavy launch vehicle ready for a Mars mission in January 2018, would put SpaceX years ahead of NASA's Space Launch System. (The Agency's deep-space capable, heavy-lift rocket isn't scheduled to debut until December 2017, and even then it will be in a round-trip, unmanned mission to the Moon, not Mars.)

What's more, SpaceX's Dragon Capsule would almost certainly need to carry crew members to and from the International Space Station flawlessly, and several times, before any astronauts depart in one destined for Mars.

There's also the question of whether Dragon's radiation shielding would be sufficient for an interplanetary excursion hundreds of millions of miles and 500 days longer than the pleasure trip (relatively speaking) to low-Earth orbit. With SpaceX planning its first crewed Dragon missions to the ISS in 2015, that's cutting things pretty close — especially given the company's habit of running slightly behind schedule.

For SpaceX to adhere to the 2018 deadline of Tito's Mars mission would be ambitious for sure - but betting against Elon Musk and his companies for being "overly ambitious" is fast becoming a rather risky wager.

No — one of the greatest challenges that must be confronted by a human mission to Mars (but Tito's especially) is the impact such a journey would have on its crew members. A 501-day Mars mission would crush the current record for longest human spaceflight by more than 60 days, and while the physical repercussions of longterm human space flight are poorly understood, we do know that our muscles and bones waste away rapidly in low- and zero-gravity environments. One of the best ways to fight the body's deterioration is with regular exercise. If engineers are to include exercise equipment in the narrow confines of a Dragon capsule, they'll have to get mighty creative. [The infographic featured here, courtesy SPACE.com, gives you an idea of the Dragon's size. Click to enlarge. See also: this excellent graphic of manned capsule size comparisons.]

All in all, Tito's is an alluring and borderline-feasible proposition, but it's positively lousy with soaring ambitions and niggling caveats. We're very interested to hear what he and his colleagues will have to say on this next week, and we will of course keep you posted.

Top image: concept art of a nuclear-driven spacecraft orbiting around Mars. Pat Rawlings/NASA